Journal of Geophysical Research: Biogeosciences最新文献_第3页

Nonlinear Elevation-Dependent Controls on Drought Responses of Vegetation Net Primary Production in the Central Himalayas 喜马拉雅中部植被净初级生产干旱响应的非线性高程控制

IF 3.5 3区环境科学与生态学

Journal of Geophysical Research: Biogeosciences Pub Date : 2026-03-17 DOI: 10.1029/2025JG009490

Jiujiang Wu, Yanqing Yang, Junli Zhao, Tao Ding, Wei Zhao

{"title":"Nonlinear Elevation-Dependent Controls on Drought Responses of Vegetation Net Primary Production in the Central Himalayas","authors":"Jiujiang Wu, Yanqing Yang, Junli Zhao, Tao Ding, Wei Zhao","doi":"10.1029/2025JG009490","DOIUrl":"https://doi.org/10.1029/2025JG009490","url":null,"abstract":"Climate warming is intensifying drought impacts on vegetation, especially in mountainous regions where complex topography mediates ecological responses. However, elevational variation in vegetation drought responses and their drivers remains unclear. Here, we assessed vegetation Net Primary Productivity (NPP) sensitivity to drought across elevations and vegetation types with multiple drought metrics in Nepal. Combining a structural equation model and random forest analyses, we quantified impact pathways and the relative importance of environmental drivers, providing new insights into drought impact. We found that drought frequency decreases with elevation in Nepal. Both the probability and intensity of drought-induced NPP loss showed nonlinear elevation patterns, decreasing before increasing, with inflection points around 3,200–3,600 m and 4,000–4,400 m, respectively. Although severe NPP loss was generally associated with stronger droughts, the convergence of loss thresholds at higher elevations reflects reduced ecological resilience and heightened vulnerability of alpine systems. Temperature emerged as the dominant driver of loss intensity and represented the most upstream climatic control in the pathway (mean β = 0.37), while vegetation condition and soil moisture, respectively, dominated the indirect regulation of loss probability and intensity. However, the drivers of NPP loss reorganize along the elevation gradient, with single factor dominance at low elevations, a temperature importance peak at ∼3,000 m, and co-regulation by multiple factors at high elevations. This study advances our understanding of nonlinear climatic stress in mountain ecosystems.","PeriodicalId":16003,"journal":{"name":"Journal of Geophysical Research: Biogeosciences","volume":"131 3","pages":""},"PeriodicalIF":3.5,"publicationDate":"2026-03-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147566678","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Gold-Standard Science in Uncertain Times — Thank You to the 2025 Reviewers of JGR Biogeosciences 不确定时代的黄金标准科学-感谢2025年JGR生物地球科学审稿人

IF 3.5 3区环境科学与生态学

Journal of Geophysical Research: Biogeosciences Pub Date : 2026-03-14 DOI: 10.1029/2026JG009838

Gil Bohrer, Xiaojuan Feng, Ben Bond-Lamberty, Hongyan Bao, Kyle S. Boodoo, Kendalynn A. Morris, Bailey Murphy, Ceara J. Talbot, Marguerite A. Xenopoulos

引用次数: 0

Gold-Standard Science in Uncertain Times — Thank You to the 2025 Reviewers of JGR Biogeosciences 不确定时代的黄金标准科学-感谢2025年JGR生物地球科学审稿人

IF 3.5 3区环境科学与生态学

Journal of Geophysical Research: Biogeosciences Pub Date : 2026-03-14 DOI: 10.1029/2026JG009838

Gil Bohrer, Xiaojuan Feng, Ben Bond-Lamberty, Hongyan Bao, Kyle S. Boodoo, Kendalynn A. Morris, Bailey Murphy, Ceara J. Talbot, Marguerite A. Xenopoulos

引用次数: 0

Quantifying Potential Nutrient Liberation Following Plant Investment in Root Exudates: Variation Across Soil Profiles and Ecosystems in the United States 植物根系分泌物投资后潜在养分释放的量化：美国土壤剖面和生态系统的变化

IF 3.5 3区环境科学与生态学

Journal of Geophysical Research: Biogeosciences Pub Date : 2026-03-13 DOI: 10.1029/2025JG009380

Rachel M. Keen, Pamela L. Sullivan, Hoori Ajami, Daniel R. Hirmas, Li Li, Alejandro N. Flores, Terrance Loecke, Karla Jarecke, Lola Klamm, Micah Unruh, Vaishnavi Varikuti, Sharon A. Billings

{"title":"Quantifying Potential Nutrient Liberation Following Plant Investment in Root Exudates: Variation Across Soil Profiles and Ecosystems in the United States","authors":"Rachel M. Keen, Pamela L. Sullivan, Hoori Ajami, Daniel R. Hirmas, Li Li, Alejandro N. Flores, Terrance Loecke, Karla Jarecke, Lola Klamm, Micah Unruh, Vaishnavi Varikuti, Sharon A. Billings","doi":"10.1029/2025JG009380","DOIUrl":"10.1029/2025JG009380","url":null,"abstract":"Plants allocate significant amounts of carbon belowground to support water and nutrient acquisition, and a large proportion of that carbon is allocated to the production of root exudates. One utility of exudates is to aid in phosphorus acquisition, but the amount of phosphorus that can be liberated by different exudates is largely unknown. We used three common exudates—oxalic acid, malic acid, and acid phosphatase (APase)—to extract phosphate from 25 soil profiles across the United States. These extracts represent the “maximum efficiency” of specific exudates at liberating phosphorus from a wide range of soil types, providing an upper boundary to constrain biogeochemical and land-surface models aimed at representing exudate-related nutrient fluxes. Our findings reveal significant variability in the efficiency of exudates to liberate phosphate across locations and soil depths. Oxalic acid exhibited the highest potential extraction efficiency overall, and its efficiency often increased in deeper horizons—likely driven by higher proportions of mineral-bound phosphorus in deeper soil layers. APase had the lowest overall potential extraction efficiency, and its efficiency typically declined with depth and had stronger associations with soil organic carbon. Malic acid potential extraction efficiency was intermediate, and depth trends were often more similar to APase than oxalic acid. Malic acid and APase showed increasing extraction efficiency at sites with higher mean annual temperature and precipitation. This study highlights the varying efficiencies of exudate compounds in liberating soil phosphorus across ecosystems and provides a framework for understanding nutrient dynamics under changing climate or land-use conditions.","PeriodicalId":16003,"journal":{"name":"Journal of Geophysical Research: Biogeosciences","volume":"131 3","pages":""},"PeriodicalIF":3.5,"publicationDate":"2026-03-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147683700","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Contrasting CO2 Fluxes Among Arctic Pond Types Are Driven by Differences in Carbon Lability, Terrestrial Inputs, and Benthic Respiration 碳不稳定性、陆地输入和底栖生物呼吸差异驱动北极不同池塘类型间的CO2通量对比

IF 3.5 3区环境科学与生态学

Journal of Geophysical Research: Biogeosciences Pub Date : 2026-03-12 DOI: 10.1029/2025JG009318

Asher J. Marvy, Christian G. Andresen, Alina C. Spera, Vanessa L. Lougheed

{"title":"Contrasting CO2 Fluxes Among Arctic Pond Types Are Driven by Differences in Carbon Lability, Terrestrial Inputs, and Benthic Respiration","authors":"Asher J. Marvy, Christian G. Andresen, Alina C. Spera, Vanessa L. Lougheed","doi":"10.1029/2025JG009318","DOIUrl":"10.1029/2025JG009318","url":null,"abstract":"Small freshwater tundra ponds are hotspots for greenhouse gas release into the atmosphere. As the Arctic warms, thermokarst processes drive changes in tundra pond geomorphology, with implications for their contribution to carbon cycling in these regions. To understand how these morphological changes affect pond biogeochemistry, we compared low-centered polygonal (LCP) ponds and thermokarst trough (TKT) ponds that are formed through ice-wedge permafrost thaw. We found substantially higher levels of carbon, nutrients, and algal biomass in TKT ponds as compared to LCP ponds located in the Arctic Coastal Plain near Utqiaġvik, AK. These differences were likely driven by TKT ponds receiving increased terrestrial inputs due to discrete thermokarst events and slumping, lateral inflow of carbon and nutrients from surrounding soils, higher lability of TKT carbon, and greater rates of benthic respiration. Together, these factors create ponds that are more productive and greater sources of CO2 to the atmosphere than LCPs. During the peak growing season (July-August), CO2 uptake from macrophyte-dominated habitat in LCP ponds compensates for CO2 release from open water, making LCP ponds net CO2 sinks (−4 ± 3 gCO2/m2/d), whereas TKT ponds are CO2 sources (3 ± 6 gCO2/m2/d), despite TKT macrophyte-dominated habitat also being a site of CO2 uptake. The net atmospheric greenhouse gas contribution of these ponds will likely be altered with high latitude warming, as air temperature influenced factors including vegetation cover, precipitation, water temperature, and thermokarsting alter rates of CO2 flux from tundra ponds.","PeriodicalId":16003,"journal":{"name":"Journal of Geophysical Research: Biogeosciences","volume":"131 3","pages":""},"PeriodicalIF":3.5,"publicationDate":"2026-03-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147565381","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Influence of Biofilms and Extracellular Polymeric Substances on High-Frequency Acoustic Backscatter 生物膜和细胞外聚合物对高频声波后向散射的影响

IF 3.5 3区环境科学与生态学

Journal of Geophysical Research: Biogeosciences Pub Date : 2026-03-12 DOI: 10.1029/2025JG009446

Willian R. Assis, Imtisaal Naeem, Lian Shen, Judy Q. Yang

{"title":"Influence of Biofilms and Extracellular Polymeric Substances on High-Frequency Acoustic Backscatter","authors":"Willian R. Assis, Imtisaal Naeem, Lian Shen, Judy Q. Yang","doi":"10.1029/2025JG009446","DOIUrl":"https://doi.org/10.1029/2025JG009446","url":null,"abstract":"Acoustic Backscatter Technique has been used to detect underwater targets and characterize seabed and river floor sediment properties. Microbial biofilms, consisting of microorganisms enclosed in Extracellular Polymeric Substances (EPS), have the potential to modify acoustic backscatter by altering the sediment topography, permeability, and porosity; however, these effects remain uncharacterized. Here, we performed laboratory experiments to explore the effects of microbial biofilms and EPS within sediments on acoustic backscatter. Our results show that the biofilm mat-like structure formed by microorganisms above the sediment bed can reduce acoustic backscatter by up to 6 dB, while EPS within sediments can increase backscatter strength by up to 6 dB, with more significant changes at lower incident angles. This study highlights the critical role of biofilms in acoustic backscatter and paves the way for detecting targets and characterizing the properties of biofilm-covered sediment beds.","PeriodicalId":16003,"journal":{"name":"Journal of Geophysical Research: Biogeosciences","volume":"131 3","pages":""},"PeriodicalIF":3.5,"publicationDate":"2026-03-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://agupubs.onlinelibrary.wiley.com/doi/epdf/10.1029/2025JG009446","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147565311","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Contrasting CO2 Fluxes Among Arctic Pond Types Are Driven by Differences in Carbon Lability, Terrestrial Inputs, and Benthic Respiration 碳不稳定性、陆地输入和底栖生物呼吸差异驱动北极不同池塘类型间的CO2通量对比

IF 3.5 3区环境科学与生态学

Journal of Geophysical Research: Biogeosciences Pub Date : 2026-03-12 DOI: 10.1029/2025JG009318

Asher J. Marvy, Christian G. Andresen, Alina C. Spera, Vanessa L. Lougheed

{"title":"Contrasting CO2 Fluxes Among Arctic Pond Types Are Driven by Differences in Carbon Lability, Terrestrial Inputs, and Benthic Respiration","authors":"Asher J. Marvy, Christian G. Andresen, Alina C. Spera, Vanessa L. Lougheed","doi":"10.1029/2025JG009318","DOIUrl":"https://doi.org/10.1029/2025JG009318","url":null,"abstract":"Small freshwater tundra ponds are hotspots for greenhouse gas release into the atmosphere. As the Arctic warms, thermokarst processes drive changes in tundra pond geomorphology, with implications for their contribution to carbon cycling in these regions. To understand how these morphological changes affect pond biogeochemistry, we compared low-centered polygonal (LCP) ponds and thermokarst trough (TKT) ponds that are formed through ice-wedge permafrost thaw. We found substantially higher levels of carbon, nutrients, and algal biomass in TKT ponds as compared to LCP ponds located in the Arctic Coastal Plain near Utqiaġvik, AK. These differences were likely driven by TKT ponds receiving increased terrestrial inputs due to discrete thermokarst events and slumping, lateral inflow of carbon and nutrients from surrounding soils, higher lability of TKT carbon, and greater rates of benthic respiration. Together, these factors create ponds that are more productive and greater sources of CO2 to the atmosphere than LCPs. During the peak growing season (July-August), CO2 uptake from macrophyte-dominated habitat in LCP ponds compensates for CO2 release from open water, making LCP ponds net CO2 sinks (−4 ± 3 gCO2/m2/d), whereas TKT ponds are CO2 sources (3 ± 6 gCO2/m2/d), despite TKT macrophyte-dominated habitat also being a site of CO2 uptake. The net atmospheric greenhouse gas contribution of these ponds will likely be altered with high latitude warming, as air temperature influenced factors including vegetation cover, precipitation, water temperature, and thermokarsting alter rates of CO2 flux from tundra ponds.","PeriodicalId":16003,"journal":{"name":"Journal of Geophysical Research: Biogeosciences","volume":"131 3","pages":""},"PeriodicalIF":3.5,"publicationDate":"2026-03-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147565310","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Influence of Biofilms and Extracellular Polymeric Substances on High-Frequency Acoustic Backscatter 生物膜和细胞外聚合物对高频声波后向散射的影响

IF 3.5 3区环境科学与生态学

Journal of Geophysical Research: Biogeosciences Pub Date : 2026-03-12 DOI: 10.1029/2025JG009446

Willian R. Assis, Imtisaal Naeem, Lian Shen, Judy Q. Yang

引用次数: 0

Capturing Spatial Gradients of Water Color and Clarity in Subtropical Reservoirs During Drought 干旱时期亚热带水库水色和清晰度的空间梯度捕捉

IF 3.5 3区环境科学与生态学

Journal of Geophysical Research: Biogeosciences Pub Date : 2026-03-11 DOI: 10.1029/2025JG009401

Malcolm S. Macleod, Nicole D. Wagner, Xiao Yang, Stephen M. Powers

{"title":"Capturing Spatial Gradients of Water Color and Clarity in Subtropical Reservoirs During Drought","authors":"Malcolm S. Macleod, Nicole D. Wagner, Xiao Yang, Stephen M. Powers","doi":"10.1029/2025JG009401","DOIUrl":"10.1029/2025JG009401","url":null,"abstract":"Reservoirs have spatial variation in water depth, suspended matter, and biogeochemistry that can influence patterns of water clarity and color. Spatial surveys with sensor-equipped boats matched in time with satellite image acquisition provide data-intensive avenues for understanding spatial patterns of optical properties within reservoirs. We combined continuous field data from high-speed spatial surveys with Sentinel-2 imagery to map water clarity and color in six subtropical Texas reservoirs during summer. Reservoir arms had lower clarity and longer dominant wavelengths than the main bodies, indicating higher concentrations of optical constituents. Because surveys took place during a period of low inflows associated with drought, color and clarity patterns may have been associated mainly with phytoplankton communities and resuspension of shallow sediments, rather than direct river inputs. Whole system analysis of dominant wavelength showed that five reservoirs reflected green (550–569 nm) over most of their surface area, suggesting high concentrations of phytoplankton biomass, and one reservoir in a clay-dominated watershed was primarily yellow to brown (570–583 nm). Water clarity spanned a wide turbidity range (3.18–95.2 NTU) and was low over most of the surface area of these systems (<1.5 m Secchi). In five bio-optical models of turbidity, the best model performance occurred between 0 and 50 NTU, with unexplained variation at higher turbidity possibly linked to optically distinct classes of suspended sediment, phytoplankton pigmentation, or dissolved organic matter. These results indicate that reservoirs can have considerable spatial heterogeneity in water clarity and color, setting the stage for future spatial snapshots that encompass interannual and seasonal variability in precipitation.","PeriodicalId":16003,"journal":{"name":"Journal of Geophysical Research: Biogeosciences","volume":"131 3","pages":""},"PeriodicalIF":3.5,"publicationDate":"2026-03-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://agupubs.onlinelibrary.wiley.com/doi/epdf/10.1029/2025JG009401","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147564822","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Capturing Spatial Gradients of Water Color and Clarity in Subtropical Reservoirs During Drought 干旱时期亚热带水库水色和清晰度的空间梯度捕捉

IF 3.5 3区环境科学与生态学

Journal of Geophysical Research: Biogeosciences Pub Date : 2026-03-11 DOI: 10.1029/2025JG009401

Malcolm S. Macleod, Nicole D. Wagner, Xiao Yang, Stephen M. Powers

{"title":"Capturing Spatial Gradients of Water Color and Clarity in Subtropical Reservoirs During Drought","authors":"Malcolm S. Macleod, Nicole D. Wagner, Xiao Yang, Stephen M. Powers","doi":"10.1029/2025JG009401","DOIUrl":"https://doi.org/10.1029/2025JG009401","url":null,"abstract":"Reservoirs have spatial variation in water depth, suspended matter, and biogeochemistry that can influence patterns of water clarity and color. Spatial surveys with sensor-equipped boats matched in time with satellite image acquisition provide data-intensive avenues for understanding spatial patterns of optical properties within reservoirs. We combined continuous field data from high-speed spatial surveys with Sentinel-2 imagery to map water clarity and color in six subtropical Texas reservoirs during summer. Reservoir arms had lower clarity and longer dominant wavelengths than the main bodies, indicating higher concentrations of optical constituents. Because surveys took place during a period of low inflows associated with drought, color and clarity patterns may have been associated mainly with phytoplankton communities and resuspension of shallow sediments, rather than direct river inputs. Whole system analysis of dominant wavelength showed that five reservoirs reflected green (550–569 nm) over most of their surface area, suggesting high concentrations of phytoplankton biomass, and one reservoir in a clay-dominated watershed was primarily yellow to brown (570–583 nm). Water clarity spanned a wide turbidity range (3.18–95.2 NTU) and was low over most of the surface area of these systems (<1.5 m Secchi). In five bio-optical models of turbidity, the best model performance occurred between 0 and 50 NTU, with unexplained variation at higher turbidity possibly linked to optically distinct classes of suspended sediment, phytoplankton pigmentation, or dissolved organic matter. These results indicate that reservoirs can have considerable spatial heterogeneity in water clarity and color, setting the stage for future spatial snapshots that encompass interannual and seasonal variability in precipitation.","PeriodicalId":16003,"journal":{"name":"Journal of Geophysical Research: Biogeosciences","volume":"131 3","pages":""},"PeriodicalIF":3.5,"publicationDate":"2026-03-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://agupubs.onlinelibrary.wiley.com/doi/epdf/10.1029/2025JG009401","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147564982","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0